Electrically-heated vessel



(No Model.) '2 SheecsSheet 1.

W. MITCHELL. ELEOTRIOALLY HEATED VESSEL.

No. 474,398. Patented May'10,189Z.

(No Model.)

.2 SheetsSheet W. MITCHELL.

ELEOTRIOALLY HEATED VESSEL.

Patented May 10,1892.

UNITED STATES PATENT OFFICE.

WILLIS MITCHELL, OF MALDEN, ASSIGNOR TO THE BUTTERFIELD-MITCHELL ELECTRIC HEATING COMPANY, OF BOSTON, MASSACHUSETTS.

ELECTRlCALLY-HEATED VESSEL.

SPECIFICATION forming part of Letters Patent No. 473,398, dated May 10, 1892.

Application filed September 5, 1891. Serial No. 404.838. the model.)

To all whom it may concern.-

Be it known that I,\VILLIs MITCHELL, a citizen of the United States, residing at Maiden, in the county of Middlesex and State of Massachusetts, have invented certain new and useful Improvements in Electrically-IIeated Receptacles and Connections Therefor; and I do hereby declare the following to be a full, clear, and exact description of the invention,

such as will enable others skilled in the art to which it appertains to make and use the same.

The chief object of this invention is to make convenient and satisfactory electrical connec- 't-ions by new and improved combinations and r5 constructions of devices with pots, boilers,

and otler heating devices inclosed in receptacles or shells from which the electric wires must be insulated.

To this end my invention consists in the devices hereinafter set forth, constructed, and comb ned as claimed.

In the accompanying drawings, Figure 1 represents a perspective view of a heatingpitcher thus arranged and provided, the interior receptacle or pitcher proper being indicated by dotted lines. Fig. 2 represents in enlarged detail view this inner receptacle or pitcher proper and its winding and the nut for holding it in place. Fig. 3 represents a similar iew of the outer shell. Fig. & represents a detail perspective view of the base. Fig. 5 represents a similar view of the recessed board into which the pitcher is set, as in Fig. 1. Fig. 0 represents a transverse section taken above the electrical connections and partly broken away to show the latter. Fig. 7 represents a detail perspective view of the grooved insulating-sleeve. Fig. 8 represents a similar view of the brass bolt making the electrical connection and its bolt. Fig. 9 represents a detail view of one of the U- shaped springs hereinafter described.

A, designates the inner receptacle or pitcher proper, which may be of copper and contains the water or other liquid to be heated; 13, its removable cover; (,3, the exterior shell provided with a handle 0, and I) the base, these constitutingthc chief parts of the liquid-heating pitcher. The inner receptacle A has an enlarged and rounded top A to rest 'on the upper edge of the outer shell 13 and a lip or nose a, extending out through a recess I in the said upper edge. The overlapping construction of the rounded top or rim A and nose a will prevent the liquid which is poured into or out of the said inner receptacle or pitcher from running down between it and the said outer shell among the coils of the wire,hereinafterdescribed. Thesaid pitcher proper or inner receptacle A has on its bottom a downwardly-extcnding stud A") preferably hard-soldered thercto,) which passes through a hole (l in the centerof thebase I). Thcend of this stud is screwthreaded to receivca nut 6 below the said base. liy tightening this nut on the said stud the said inner receptacle or pitcher is drawn down and the said pitcher, outer shell, and base are fastened together. The said shell C has in its lower edge on one side two semicircular recesses C and C which lit against similar recesses DD in an upward annular flange D of the base D, each pair of openings 0 D and C D forming a circular opening.

F F designate two insulatingsleeves, which fit into these openings, respectively, each sleeve having an annular groove fto receive the edge of the said shell. Through the central bore of each sleeve a metallicbolt G or G extends, being held in place by a nut g. To the inner ends of these bolts G G the ends of a wire II are attached, which is coiled spirally around the inner receptacle or pitcher A at such intcrvalsbetween the coils as I have found most effective for heating purposes. As shown, only one winding or layer of coils is employed; but there may be six or seven or more of these windings. Insulating material is of course interposed between the first winding, such as shown, and the pitcher A and between the successive windings or layers of coils and the proximate coils of each layer or winding; or the wire may simply be coated throughout with insulating material.

Each metallic bolt G or G has its outer end formed into an enlarged head G This head fits into the jaws of a narrow U-shapcd spring I or I, which is outwardly curved at its upper edges and fastened at the bottom by some source of electricity, the-bolts G G, and

- tightening.

is then setinto the recessed bottom board and the coiled heating-wire H.

In putting the pitcher togetherjfor use as a liquid-heating device I first wind the wire H, as described, on the inner receptacle or pitcher proper. I then set it into the outer-shell O on the base D, insert the insulating-sleeves F F into the openings described, and clamp these parts together, as described, by turning the nut on the stud belowthe base. The ends of wire H are .wound on or attached to the inner ends of the bolts G G before this fastening or The heating-pitcher as [a Whole the heads of the bolts enter the jaws of the springs, completing the circuit, as stated. The insulating-sleeves are preferably of porcelain or earthenware. Pulverized soapstone may be filled into the-space between the outer shell andthe inner receptacle or pitcher proper. The connections hereinbefore described may be used with ovens or other inclosed heaters. Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is-

1. In combination with an inner receptacle and an outer shell, an electrical resistance in the space between them, insulatingsleeves extending through the said shell, and conductors extending through the said sleeves and connected to the ends of the said resistance erases for establishing an electrical circuit through the latter, substantially as set forth.

2'. In combination with an outer shell and a perforated base, an inner receptacle having a stud extending from it down through the said base, insulating i sleeves extending in through openings in the said base and shell, and a device below said base engaging the said stud to clamp the said parts together, substantially as set forth.

3. In combination with a recessed bottom board or support and U-shaped springs secured therein, wires forming part of an electric circuit in contact with the said springs, and an electrically-heated receptacle having protruding conductors, and a resistance in contact with them, the said conductors entering the said springs when the said receptacle is set into the said bottom board to complete the electric heating-circuit, substantially as set for h.

' 4 Au inner receptacle and wire wound WILLIS MITCHELL. Witnesses:

EDWIN W. PIERCE, PELATIAH R. SRIPP. 

